A color electrophotographic image forming apparatus which simplifies a
configuration in which a rotary is rotated to change over respective
developing devices to a development position to reduce the costs and save
the space, and which simplifies the changeover operation to reduce an
operating time. The image forming apparatus sequentially moves and
changes over the respective developing devices supported by the rotary to
the development position which faces a photosensitive drum by the
rotation of the rotary. The rotary is rotated to move the developing
devices. A cam is rotated integrally with the rotary, and thereby
abutment portions of the cam are abutted against a regulating rotatable
member so that the developing devices are spaced from a photosensitive
drum. In a state in which the developing devices are abutted against the
photosensitive drum, the cam is spaced from the regulating rotatable
member by recesses of the cam.